1. Field of the Invention
The present invention is related to a method for nucleic acid hybridization, particularly, the method of using microfluidic chip for nucleic acid hybridization.
2. The Prior Arts
Regarding clinical diagnoses and treatment, rapid identification of causative pathogens can effectively improve clinical outcomes. The conventional identification of bacteria depends on the colonies growth on the cultured medium and examining their morphological and the expressed biochemical characters. The whole process costs around 4 to 5 days.
Using specific nucleic acid as probe to analyze the test nucleic acid via hybridization is one of the commonly used methods for verifying whether or not the DNA of the specimen contains the desired gene(s) or gene segment. Known analysis of hybridization comprises the following steps: primarily, utilizing blot or blotting techniques to transfer the test nucleic acid to a substrate, for example, a membrane; then, proceeding the hybridization using nucleic acid as probe with specificity; finally, presenting the result of hybridization by methods such as color reaction, luminescence, or radioactive emission according to the marker molecule of the nucleic acid probe.
For the known blotting technique, the test nucleic acid was placed on the surface of a membrane in the form of droplet; for the purpose of eliminating the possibility of nucleic acid being washed away during the wash step after the hybridization, heating or ultraviolet light exposure was applied to ensure that the test nucleic acid crosslink firmly on the surface of the membrane. If the membrane was placed inside a microfluidic chip, the above heating process generates heat and is likely to cause slight twists of the microfluidic channels resulting in leak of fluid. Slow heat reduction is also a drawback which leads to a longer time required for the crosslinking of the test nucleic acid. Besides, like the test nucleic acid, diffusion of nucleic acids that served as probes can only happen on the surface of the membrane which allows probes to move in Brownian motion and search for complementary nucleic acids. Therefore, known nucleic acid hybridization methods undergo multiple operative procedures and requires reaction time of ten hours or above. Hence, for examinations that require immediate results, known nucleic acid hybridization methods are incapable of completing the process in a short period of time. Besides, it is also very inefficient if a large amount of time and agent were still to be spent on simple nucleic acid qualifying examinations.
Prevention and accurate diagnosis are important parts of public health and disease control. Moreover, accurate diagnosis is the foundation of effective treatment. Method or device of nucleic acid hybridization that is able to simplify the step and time of nucleic acid matching as well as eliminate background interfering signals can effectively reduce the time and cost of both normal or large scale batch examinations. However, currently the market still lacks an accurate, cost-effective, easy-to-store, and highly efficient nucleic acid hybridization technique.